Dolby Vision Profile 4 (Legacy)
Dolby Vision Profile 4 is a legacy dual-layer ten-bit HEVC format with an SDR-compatible base.
Use this record when identifying older Dolby Vision media:
| Legacy property | Profile 4 |
|---|---|
| Coded picture precision | Ten-bit HEVC |
| Structure | Base plus enhancement |
| Enhancement size | One-quarter of the base picture's pixel count |
| Base compatibility | SDR |
| New-application status | Listed by Dolby as not supported for new applications |
Why can a ten-bit base be SDR?
Precision identifies the available sample levels. The transfer and color interpretation identify what those levels represent. Profile 4's ten-bit base has an SDR-compatible interpretation; a supporting Dolby Vision route uses the complete prepared presentation with its enhancement and metadata.
That separates it from Profile 7, whose compatible base is HDR10. Counting two layers in both files would leave their base-light relationships unresolved.
Does SDR output mean Emby Server converted the file?
Not necessarily. An app can use the compatible SDR base after receiving supported source data. A server conversion is another route that creates a new delivered stream. The server's playback method and delivered media information locate which operation occurred.
The legacy status describes Dolby's direction for new applications. For an existing archived source, identify the actual decoder and presentation path used, then preserve that source record alongside any newly prepared viewing version.